Shoe sole



Dec. 7, 1948. H Q KNELLWOLF 2,455,500

SHOE soLE v Filed Aug. 18, 194s 1N V EN TOR.

HANS` 6. KNELL WLF BY www A T TRNE Y Patented Dec. 7, 1948 SHOE SOLE Hans C. Knellwolf, Zurich, Switzerland Application August 18, 1943, Serial No. 499,298 In Switzerland July 11, 1942 Section 1, Public Law 690, August 8, 1946 Patent expires July 11, 1962 2 Claims.

The emciency of the human foot has decreased from generation to generation with the development of civilization. Many attempts have been made, it is true, to give the weak fo-ot a hold by constructing sturdy boots with strong uppers, extended heel-caps, stiffened insoles, etc. The results were extremely unsatisfactory. The feet were certainly kept in their natural position by these boots, but hindered in their free movements by their covering, which acted like a corset and thus prevented the foot from articulating naturally when walking.

The skeleton yof the foot must be held toegther by the strength of its muscles and ligaments. Muscular strength can only be acquired, however, when the muscles are made to perform work. Thus when the boots or shoes perform a large part of the work of these muscles, the latter are obviously weakened and the support of the foot bones is no longer effected by normal muscular strength, but mainly by the further acting as a kind of an armor. If the foot would only be used to support the body in a stationary position, the requirement for proper support during the lifetime of the wearer could be satisfied by the use of continuously reinforced shoes. For walking purposes, however, muscular strength is required which, therefore, must be exercised and improved by all means. It is, therefore, inopportune to support the foot to such an extent that its muscles and tissues are relieved of the work.

Most people wear out their boots or shoes On the outside of the foot, the latter articulating diagonally towards the small toe, because the inner longitudinal of the shoe is supported much too far forward and the design of the shoe generally in use neglects the big-toe side of the foot and causes an outward slant.

Research work carried out over a number of years has led to the conclusion that excessive support on the inside of the foot and particularly of the arch, has far more detrimental effects than was generally known. The big toe, in particular, is to a certain extent relieved of its normal work. As the strong bending muscles of the instep, the consequences of their inactivity, i. e., weakening of these muscles, must in time have disastrous eects on the foot. For this reason the big toe must be given more opportunities for performing work, i. e., of strengthening the appurtenant muscles. This, however, cannot be achieved, as has been tried so often, by changing the shape of the insole, that is, transferring the weight to the inner (big-toe) side of the foot,

as the ball of the big toe would be grossly overburdened and commence to ache.

According to the present invention this aim is achieved by a-shoe sole in which the exibility yof the sole is greater in the direction of the foots articulation towards the big toe than in the other directions.

By this means the muscles of the big toe can be compelled to perform more musclestrengthening work, as when one walks barefoot on soft ground. The result is a healthy, elastic gait, a natural exercise for the muscles -of the big toe and thus, too, a strengthening of the arch carriers weakened by the various deformations of the foot.

In the attached drawing one specic embodiment of the object of this invention is depicted, wherein- Fig. 1 shows a shoe seen from the sole;

Fig. 2 an illustration depicting the shoe with the sole partly removed;

Fig. 3 a cross section through the front part of a shoe, and

Fig. 4 a cross section through the front part of the shoe in a second specic embodiment of the invention.

As shown in the drawing, the sole of the shoe is reinforced by two stiff bars I placed in a slanting direction through the sole and made of steel, iron, metal, wood or plastic material, etc., these bars extending from the small-toe side of the front part of the foot to the big-toe side of the middle part of the foot and at right angles to the direction of the foots motion towards the big toe. Thanks to these bars the flexibility of the sole is greater in the direction at right angles to them than in the other directions, so that the motion of the foot automatically proceeds towards the big toe. By this means the big toe is compelled to increase its muscular activity and the resistance powers of the foot are enhanced. As shown in Figs. 2 to 4 bars I can also be placed between the outer sole 2 and the insole 3. Instead of two bars I a single bar may also be used.

In Figs. 2 and 3 bars I are fitted between outer sole 2 on the one hand, and frame 5 and frame filling 4 on the other.

In the specific embodiment depicted in Fig. 4. bars I are placed immediately beneath the insole, i. e., tted between the latter and filling 4l which is bedded in the same layer as frame 5.

It is also possible to fasten the bars externally on the outer sole, in which case they must be recessed in grooves.

In the case of Wooden clogs and such like types of footwear the soles are made of rigid material. In order to make them exible in the direction of the articulation towards the big toe the sole must be subdivided by at least one joint whose axis is at right angles to said direction of movement. To subdivide wooden soles and to make them exible by providing them with joints is not new. but hitherto they were made exible in the direc-` tion at right angles to the longitudinal axis of the foot. In the footwear here described flexibility is, however, provided in such a manner that the foot is compelled to articulate 'twalrdsfthe big toe.

From the foregoing description taken' in Aconnection with the accompanying drawings, the advantages of the construction and' method' of use will be readily understood by those skilldiri the art to which the invention appertains, and while I have described the principle, together with the device which I now consider to be the best embodiment hereof, I'desire to have it understood that the device shown is merely illustrative and that such' changes may be made when desired as iall within the scope 'of the appended claims.

Having thus described my invention, I claim as new and`V desireto` secure' by Letters Patent:

l. A shoe sole having at least one bar of a rigid material Iocatedin'side of said sole, said bar extending at an angle' relative to the longitudinal 1' portion yof the big toe side.

HANS C. KNELLWOLF.

-REFERENCES CITED Thefollowingrreferences are of record in the yiile of this patent:

UNITED STATES PATENTS Nrnbe Name Date 152,114 Hunter June 16, 1874 1,845,031 Arthur Feb. 16, 1932 20 f 1,856,377 Dettelback -1.4----1. May 3, 15932 2,290,390 Stewart V.. A july 21, 1942 Number vCountry 'fijate 458,189 Great Britain 1 -`Dec'. -15, 19'36 460,321 Germany s 'May 24, 1-9'28 i 461,028 Germany Jun '11, I1928 561,965 Germany ctl "20', l32 

